MILWAUKEE — Milwaukee has an ever-growing and changing skyline, and I'm not talking about the buildings. Instead, I'm talking about what is on top of those sky rises: green roofs.
Those are roofs constructed to have gardens, plants, and grass embedded in the fabric of the ceiling. It's not just a planter box on top of cement, it's truly grass as the roof. These plants and grasses are dying and growing all the time. In fact, these roofs serve an incredibly important function.
“So the green roof was designed to save up to a million gallons a year. We can say that over the ten years we’ve had it, it's actually surpassed that performance, so around 11 million gallons in total," Aryton Bryan, an environmental healthy and safety manager at Rockwell Automation, said.
On top of Rockwell's roof next to the clock tower is a 49,000 square foot green space that captures and absorbs rain.
It’s saving water by absorbing rainfall, instead of it sliding off roofs and going into sewers.
When there is too much rain, like there was on Aug. 7 and Aug. 8, Jones Island, Milwaukee's water treatment facility, can’t handle the sudden high volume of water coming. Instead of the water being treated, it’s allowed to be spilled directly into our streams, rivers, and lakes, bringing pollutants and sewage with it. That is the first time it has happened in 2021. It tends to happen a few times a year.
Green roofs help prevent that from happening.
“So the more green roofs we have, we're enabling out cities to be sustainable, not only from an infrastructure perspective, but also from a day to day and environmental health perspective.”
Rockwell's large square footage plays another important roll in the city's ecosystem. It actually helps cool down the city too.
“So, in a city, typically temperatures are a couple degrees higher than other areas, because the sunlight doesn’t reflect the same way on green space," Majo Thurman, the director of environmental health and safety at Rockwell, said.
It's called the heat island effect. Green spaces absorb heat, which helps bring down the overall temperature. On the other hand, blacktops, buildings, and concrete reflect heat, creating higher overall temperatures.
Obviously, the Rockwell roof isn't changing Milwaukee's temperature by a full degree, but with enough green spaces, the temperature of the city can be affected.
Rockwell isn't the only building with a green roof. In fact, according to the Milwaukee Metropolitan Sewage District, the organization that has helped establish many green roofs, there are 68 in the city that take up about 11 acres of space.
Another green roof of note is the one at the Grohmann Museum in downtown Milwaukee.
“This is a way where we could save about 50 percent of that water from running into sewers and drains, effectively, and now, we are putting it to great use in providing the water needed for our rooftop garden," James Kieselburg, the director of the Grohmann Museum, said.
Their green roof is also a sculpture garden with 18 bronze statues open to all museum attendees.
“So, we display art and industry and engineering. These sculptures go right along with that theme in that they are all working figures.”
An interesting juxtaposition of old and new is created on top of this particular roof. Eighteen bronze statues of giant working men commemorate the history of labor, industry, and engineering. Those pieces of art are surrounded by modern environmental practices. It's a blending of old and new.
“Well, I think it is great to have these urban oases," Kieselburg said.
Another added bonus of green roofs is that they save on building energy costs. Given that they absorb heat, it helps insulate the building more efficiently. Furthermore, green roofs, like Rockwell's, will last around 40 years, which is much longer than the average roof, according to Majo Thurman, the director of environmental health and safety at Rockwell.
Not everyone can have a green roof, but you can help. Simply put out any barrel, container, or thing that can catch water, then reuse it at a later date.
So the next time you are admiring the skyline of Milwaukee or thinking that you wish it would grow more, just know that on some of those rooftops, there are plants and grasses growing every single day.